Comparative evaluation of conventional and advanced HVAC line protection algorithms: a case study

This paper presents a case study that compares differential and distance protection algorithms for high voltage alternating current (HVac) transmission lines. Both conventional protection methods, which rely on phasor measurements of voltages and currents, and more advanced algorithms are evaluated. These recently published advanced methods employ the biweight midcorrelation (BWMC), dynamic time warping (DTW), and Bayesian inference techniques. First, all algorithms are tested against data recorded by field IEDs during an actual fault on an existing 440 kV transmission line from the Brazilian interconnected power system. The fault detection speed of each method is also evaluated and compared with the response of the line differential protection function embedded in the field IEDs. Then, to ensure a robust analysis, the fault scenario is reconstructed in the ATP/EMTP electromagnetic transient simulation software, and from this base model, additional test cases are simulated to further test the studied protection algorithms. This comparative study highlights the practical implications of employing innovative versus conventional phasor-based protection schemes, further reinforcing their potential for application in modern power systems.